The present invention relates to closures for styrofoam cups and the like for beverages, and particularly to such a closure lid or cap which permits the beverage to be drunk with the lid in place, yet resists spillage of the beverage when a cup equipped with such a cap is jostled or carried in a moving vehicle.
Upwardly open beverage cups of foam plastic material are commonly provided as disposable containers for beverages such as coffee and tea sold to be consumed off the premises of the seller, or to be consumed aboard moving public conveyances such as trains and airplanes. It is well known to cover such cups with tightly fitted caps which prevent spillage of the beverage so long as the cap is in place. However, most previously available caps must be removed from the cup before the beverage can be drunk. This presents the risk of spillage of the beverage when one attempts to drink from such a container in a moving vehicle.
Openings have been made in caps to permit insertion of drinking straws, but it is generally not desirable to use a drinking straw for consumption of hot beverages. While the use of a drinking straw is safer, in terms of avoiding spillage, an important part of the enjoyment of many hot beverages is the inhalation of the aroma of the beverage as it is being sipped. It is therefore desired to have a cap which limits spillage of a hot beverage, yet permits the aroma to be enjoyed as the beverage is consumed.
Previously-known attempts to provide a satisfactory solution to this problem are disclosed in Ruff U.S. Pat. Nos. 3,938,695 and 4,085,861. Ruff discloses beverage cup closure lids having depressions whose bottom surfaces are provided with holes through which the beverage can move upwardly into the depression to be drunk without removing the cover from the cup. The cap remains in place above the bulk of the beverage contained in the cup or similar container, even as the beverage is consumed. While such lids do provide a certain amount of limitation of the spillage of a beverage from cups, the provision of holes in the bottom of the depression of such a lid permits an unnecessarily great rate of flow of beverage through the cap, should the container be overturned.
Barnett U.S. Pat. No. 3,806,023 and Wall U.S. Pat. No. 2,601,767 disclose covers which define separate reservoirs atop the main reservoir of a cup or similar container, but which similarly appear to permit an undesirably large rate of flow of beverage contained within, should the container be overturned.
Dibrell U.S. Pat. No. 3,797,696 discloses a non-spill container closure lid having cuts defining depressible flaps which provide some limitation of the amount of possible flow from within the container into an annular channel defined about the periphery of a central dome portion of the lid.
None of the previously available caps for beverage containers of which the present inventor is aware, however, have provided a completely satisfactory, yet inexpensive, solution to the problem of limiting spillage of hot beverages carried in disposable containers for consumption within a moving vehicle. What is desired, then, is an improved cap for a hot beverage container and the like, which permits the beverage to be drunk from the container while the cap remains in place, which permits only a limited rate of flow of fluid from within the container as a result of sudden movement or of the container being overturned, which permits the aroma of the beverage contained within the container to be enjoyed, and which is economical to produce, transport, and store.